Correlation between Sleep Disorders and Function in Children with Spastic Cerebral Palsy.

Objectives
The aim of the present study was to explain the correlation between sleep disorders and function in children with spastic cerebral palsy (4-12 year).


Materials & Methods
This cross-sectional study was carried out on 62 children with spastic CP (8.98±1.46 yr) recruited from rehabilitation clinics of Tehran, Iran in 2017. The Activities Scale for Kids, The Sleep Disturbance Scale for Children and the cerebral palsy Quality of Life questionnaire for Children were utilized in this study. Data were analyzed using SPSS software.


Results
Children with sleep disorder and arousal disorders had lower family health, lower quality of life and lower level of independence in their activities (P< 0.05).


Conclusion
These results emphasize on the necessity of more attention about sleep disorders and family health problems in children with cerebral palsy.


Introduction
Cerebral palsy (CP) is a group of non-progressive disorders in motor and posture occurring in developing fetal , that cause in activity and function limitation s (1) Children with CP have many problems in their life. The problems vary according to many reasons including the brain lesion area and CP type (2). These problems may impair the ability to perform daily life activities, as well as limiting social participation (3).

Considering to International Classification of
Functioning, Disability & Health (ICF), function refers to an total term that embraces both activities and participation (4). Function is often a significant drive of activities of daily living ability, quality of life development, engaging in personal care and social participation. Functional impairment can also cause cognitive, motor, communication and structure decline to accelerate (5). One of the problems that may affect the function of children with CP is sleep disorder.
There has been a focus in the literature on sleep disorders and writers stated that sufficient sleep has an important role in people's health (6). Sleep plays vital role in brain function and systemic physiology of many body systems (6). This issue is more highlighted in children with CP as existing research on sleep disorders in children with CP reported that 23% of CP children have sleep disorders (with the mean age of 8 yr and 10 months), that is regarded as high when compared with 5% in the general population (7). This is probably due to several common factors in CP including muscle spasm, other types of musculoskeletal pain, and decreased ability to change body position during at nights which may all contribute to sleep difficulties and are also related to the primary motor impairment (8). Consequents of Sleep problems are: decrease motivation and concentration , cause in daytime sleepiness, mood disorders, memory deficit, and immunity decline (9) It may result not only in behavioral and neurological changes but also in families' psychical health (7). Sleep problems in children with motor disorders increase need for parental night-time attention. It is also one of the primary reasons for parent's stress who have children with chronic illnesses or are handicapped (10) Despite the fact that function is an important issue in children with CP and that sleep disorders are probably an aggravating factor of function in children with CP, but the scientific evidence to support that is meager (11).
Regardless the investigations about several problems in CP children separately on quality of life (QOL) or sleep problems or particularly motor dysfunction, (7,(11)(12)(13)(14)(15)(16)(17)  Subjects who participated in the study were explained about the study and the consent forms and related questionnaires for data collection were filled in a session lasted for one hour by the parents. validity and reliability of the Persian version were also approved (22).

QOL Measurement
QOL was assessed using the CP QOL-Child questionnaire. The CP QOL-Child is a conditionspecific QOL questionnaire designed for children with CP to assess well-being rather than ill-being (23). It has two copies (self-report, caregiver report). The second copy was used (caregiver report for 4-12 yr old children) and it contained 66 items in 7 domains: social well-being and acceptance 1 , functioning 2 , participation, and physical health 3 , emotional well-being 4 , access to services 5 , pain, and impact of disability 6 and family health 7 . Items response ranged from 1 (the most dissatisfied) to 9 (the most satisfied). The validity and reliability of this measure were obtained in Iran in a way that Cronbach's alpha ratio ranged from 0.61-0.87 and reliability ranged from 0.47-0.84 (24).    in children with higher disorder of arousal (Table 4).

Sleep Disorders Measurement
Moreover, the comparison of the QOL total score between children with sleep disorders and those without sleep disorders using independent t-test showed that the QOL total score mean was lower in children with sleep disorders (406.97±62.33) than children without sleep disorders (419.9±49016).

Discussion
Sleep disruptions have substantial adverse short and long-term functional consequences (6). Our results showed that children with CP experience had significantly high frequency of sleep disorders compared with normal children. This difference is more likely due to cognitive, emotional and physical health problems in children with CP that can, in turn, increase the likelihood of poor sleep performance (28), and decrease the ability to change body position during the night which may all contribute to sleep disorders (8).
One of the secondary aims of the present study was to compare the sleep disorders total score Iran J Child Neurol. Summer 2019 Vol. 13 No. 3 based on children's demographic characteristics (gender, age, CP type, GMFCS levels, MACS levels and cognition levels). There was significant relation between age and sleep disorders, in agreement with some other studies (12,29,30).
Sleep disorders in girls were higher than boys, in agreement with another study (12). The higher prevalence of depression and mood disruption in girls had effects on sleep quality and related to this result (31), disagreement with Cohen et al. study (32). Moreover, there was not a significant relation between sleep disorders total score and CP type, GMFCS levels and cognition levels. One probable explanation for the absence of significant relation is that all of our samples were spastic CP which have mostly the same problems. These results are in agreement with other studies that found no significant relation between sleep disorders and CP type (12), (29). Furthermore, there was not any significant relation between sleep disorders and GMFCS levels (7,30).
The main purpose of the study was to compare the relation between sleep disorders and function, the quality of life and the activities (according to ICF), in children with CP. There was not any significant relation between them. However, sleep disorders total score was higher in children with low activities independence and low QOL, low function. Higher sleep quality leads to higher health condition and higher health condition causes better quality of life, better activities level and, therefore, better functional independence. More additionally, sleep disorders may result not only in behavioral and neurological changes (body structure and function) but also they change psychical health of families (environmental factor) that is probably an aggravating factor in terms of QOL of an individual with CP (environmental factor) (7,8). According to ICF, all these personal and environmental factors can affect children's health and functional condition (4). Moreover, if we consider sleep disorders one by one, or QOL one by one, we will found a significant relation between family health and disorder of arousal. Families' level of welfare and health certainly leads to the more deduction of child many problems. Disorder of arousal depends on many problems in daily life. When the child's daily problems and mental disturbance increase because of families' health and welfare problems, he or she won't relax and consequently disorder of arousal will increase too. The results are in agreement with a study that found environmental factors and caregivers' behaviors to also contribute to children's sleep disorders reduction (15).
One limitation to the present research was that we designed the study as a cross-sectional descriptive study, and the frequency of sleep disorders was very high and we did not test the two groups, those with sleep disorders and those without sleep disorders in equal members. However, this resolved by statistical analysis as possible as we could. It is recommended to repeat the study in a large group of children with CP and its other types too.

Acknowledgements
Our sincere thanks and appreciation to all the children who participated in the study, the clinics head and head of occupational therapy departments.
No fund was received for this study.

Author`s Contribution
ZG participated in designing the study, scientific collection of information, drafting the paper, analysis and interpretation of data SAH participated in conceptualization, designing the study, interpretation of data and revising it critically for important intellectual content NAF participated in conceptualization, designing the study, interpretation of data, and scientific collection of information and revising it critically for important intellectual content.
MR participated in analysis, interpretation of data and designing the study.
All authors agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.